CD8A and neoplasm: To understand the parameters governing immunotherapy response and resistance, a framework of three tumor-immune phenotypes has been established based on histopathology: (I) inflamed, in which CD8 T cells infiltrate the tumor parenchyma (II) excluded, in which CD8 T cells accumulate at the tumor–stroma boundary and (III) desert, in which CD8 T cells are mainly absent2,3.